The geek factor of what you're about to read is probably close to redefining 'geek'.You have been warned.

Here goes...As a zip file has it's specifications in the end, while most other files has it in the beginning(header), you can concatenate a zipfile in the end of another file if that file has a header that defines it's length (.gif, .wav, ... you name it!). This way all you need to do is to rename it *.zip for the OS to read it as an archive or, as a .gif(if that's what you've got) to open it as a picture. In the case of Linux, omit the suffix and the OS will read the magic numbers in the beginning of the file and treat it accordingly.